Radio frequency transformer



Dec. 1, 1931. c. R. BINDER .1,834,571

RADIO FREQUENCY TRANSFORMER Filed April 29, 1929 -ummm Innungw SS L5 Patented Dec. `1, 1931 PATENT oer1er,-.jI

GEonGE n. BINDER, or mvnnslnii, ILLINoIs v mimo FREQUENCTRANsFoRMEn mpi-cation nmd' Apnji ze,

The present invention is'directed to a radio frequency'transformer circuit, or more particularly to a radio frequency transformer used in a radio frequency circuit.

One of the obj ects of the present invention is to provide a novel and improved radio frequency transformer which will give the maximum selectivity commensuratewith reason- `able voltage amplification. c

v bei' of turns or coils of wire in the secondary so as to reduce the resistance in the secondary,

' thereby increasing the selectivity.

rlhese and otherV obJects are accomplished by providing a constructionV and an arrangement of the various parts 1n the manner hereinafter described` and particularly pointedl 'I' out in the appended claims.

Referring to the drawings, Fig. 1 is a schematic drawing of'a simple regenerative thermionic vacuum tube circuit 4such as is well known in the art.

f Figg is a'sche'matic drawing representing the arrangement of the primary and secondprimary `to secondary lis, very high. Thisv ary of the transformer to which the invention applies, and c Fig. 3 is a side elevational view of the coil showing the mechanical arrangement of the primary and secondary of the transformer.

The present invention is directedtoa radio frequencyy transformer in which the maximum selectivity is attainedby making the coupling as close as possible andthe number of turns as low as possible. V

It is well known in the art that resistance in the secondary circuit mitigates against the selectivity of this circuit. In this invention, coupling between the coils is made very close which means that the energy transfer from high ratio of lenergy transfer from primary to secondary is attain'edin the ordinary radioV j frequency transformer by having a llarge,

Vacter Cy and ,connectedup with the first ten `ten turns are wound sixteen turns; ,of the 1929. serial No, 358,8o2l i number of secondary' turns placed in inductive relation tothe transformers prlmary.l VThis large number of turns induces undesir-V able resistance into. the secondary,"thereby impairng thef'selectivity',' although Athe :desired high Iratio of energy transferis Securedl The present invention ,secures the samehigh ratio of energy transfer byplacing ythe turns of thefsecondary in closer inductive relationto the turns lof the primary lsothat thejsamedegreeof energy transfer maybe attained by the use of fewer turns in thefsecondary. Thelelimination ofrthese additional turns in the secondary, ofcourse, reduces the resist-ance as is wellknown, in the ci secondary circuit, thereby giving a maximum selectivity consistent with the givenv energy transfer. n i

In Fig. 2, the fifty turns represented by reference .character A is the tickler' coil in the ordinary .regenerative vacuum tube circuit. The first tenl turnsof the" primary indicated bythe reference character Cis wound clockwise. All the turns on the coil wound in a. clockwisejdirection and vindicated byY ref- A7;

' erencev character ,l-:represent thesecondary ofthe radio frequency transformer. VAll. the

other turns wound in1 a counter-clockwise v'direction and indicatedby the reference 'charturns Cv represent the primary of the radio frequencytransformer. As shownin/Fig. 1,

' the primary or first ten ,turnsindicated at C is placed iny series with 'the antenna and ground, asv indicated at D. v The seconda-ry of the radio -rfrequency transformer is connected in the grid circuit as indicated at E, and shunted by a variable condenser, as shown at F, as is common in the practice.

The manner in which the coilis `wound is A90 as fol1ows2xThe primary and secondary are preferably wound on a paper tube as iindicated at G, Fig. 3 in which ten turns ofthe primaryf are firstwound ina clockwise di rection on oneend of the tube,` atthis point 05 a 'tap being brought Voutand` ten turns'of the i same'primary arefwound ina counter-clockwise direction adjacent. theten turns previously wound. VVVo'und adjacent the' last secondary in a clockwise direction. lVound adjacent the last sixteen turns is a single turn or a continuation of the previous primary turns. Wound adjacent the previous single ary which are a continuation of the previous turns of the secondary. Wound adjacent the four turns are three turns of the primary wound in a counter-clockwise direction. The' end. of' this last.' three tu .ns lterminates as isindieated at H. found adjacent the previous.- last three turns are another three turnsy ofv the primary wound in a` counter clockwise direction, the beginning; of' which -ren'iains unconnected as shown at H. Wound adjacent the previous three turns are sixteen turns of the secondary which are a rcoi'itinuationef the previouswinds of the secondary and` are wound. in. a: clockwisev direction.. found adjacent the" previous sixr teen turns is a single turn of the primary whichis a continuation of the pnevious three turns of the primary andi is wound" counterclockwise.. lVound adjacent.' the last' previous one turn are eight turns of the secondary which. isa continuation` of the' last previous sixteen turns of the secondary.. Vound adjacent the last: previous eighti turns is a single. turn of the primary' which is a continuation of the last' previous turn of the primary.. Wound adjacent the last single turn; areV eight turns of. the secondary which area continuationof; the previous eight turns of the'secondary.` lrVound adjacent the last previous eight turns are ten turns of` the primary which area continuation of the last previous single turn of the primaryi This last ten turnsareconnected with the ground` ItzWill be noted thathy having the primary C broken as shown at H and Hf andfhaying the aeriali and ground connected in series with the first ten turns of the primary C that the selectivity'v of the transformer is increased to maximum.

Vhat I claim as my invention and-desire to secure by' Letters Patent isi:`

l. A radio frequency transformer having its primary and secondary interwoven on substantially a single cylindrical surface with certain coils running in a clockwise dircction and certain others in a counter-clockwise direction.

2. A. radio frequency transformer comprising a. cylindrical core having a major portion of its primary wound in a counterclockwise direction and its secondary wound in a clockwise direct-ion and interwoven with the primary, whereby a maximum close coupling is attained, thereby increasing the selectivity of the same.

3. In a radio frequency transformer comprising a cylindrical core having the major portion of its primary and secondary coils interwoven on substantially a single cylindrical surface and wound in opposite directions so as to increase the selectivity of the same to a maximum.

4. A radio frequency transformer having a primary andf secondary coil interwoven, the primary being broken circuited whereby the' maximum selectivity is attained.

In testimony whereof I have signed my name to this specication, on this 11th day of Aprih, A. D: 11929;,

. GEORGE R.. BINDER. 

